Reproductive biology of the female little mastiff bat,Mormopterus planiceps (Chiroptera: Molossidae) in Southeast Australia

The reproductive biology of the female little mastiff bat (Mormopterus planiceps) was studied from specimens obtained throughout the year in southeast Australia, within the region occupied only by the long penile form of this species. Mormopterus planiceps appeared to undergo a single pregnancy each year and was monotocous. Conception occurred during late winter/early spring after a protracted proestrus, during which the uterine/vaginal epithelia attained an extraordinary thickness; spermatozoa were present in the uterine corpus, vagina, and intramural oviduct for at least 2 months prior to ovulation, although only those present in the oviducts were entire and thus appeared to be viable. Following ovulation, a massive postovulatory infiltration of phagocytes occurred; and the thickness of the uterine corpus epithelium was dramatically reduced. As in other molossids, the tract was bicornuate and dextrally functional. The length of gestation was difficult to determine because early embryonic stages, up to implantation, appeared to span several months (late July/August/September) as did parturition (December/January). Growth of the young was slow; nevertheless, females attained sexual maturity in their first year. Several unusual features included the presence of a long os clitoridis, and tubuloalveolar sudoriferous and associated lobulated, sebaceous, paravaginal glands, which surrounded and emptied into the lower vagina. A deep fornix anterior and lateral to the cervix probably serves to receive the secondary glans penis. The epithelium of the uterine corpus was stratified and indistinguishable, in its cytology and cyclicity, from that of the vagina; furthermore, it lacked a glandular endometrium. This portion of the female tract likely receives the elongated primary glans. These findings are discussed in relation to other Molossidae and to the reproductive biology of male M. planiceps. Although the number of animals sampled was relatively small, the data suggest that this species does not exhibit the usual temperate molossid pattern of late winter/spring coincidence of spermatogenesis and ovulation. It would seem that pregnancy may begin, at least in some individuals, during the inhospitable winter months (when epididymal and uterine spermatozoa are abundant but spermatogenesis has largely terminated) and that additional conceptions continue into the early spring. The occurrence of sperm storage in both sexes of this species is unique among Molossidae studied to date.     

Intrachromosomal distribution of telomeric repeats in Eumops glaucinus and Eumops perotis (Molossidae, Chiroptera)

The location of chromosomal telomeric repeats (TTAGGG)_n was investigated in two species of the Molossidae family, Eumops glaucinus and Eumops perotis. The diploid chromosome number (2n) is 40 in E. glaucinus and 48 in E. perotis and the fundamental numbers (FN) are 64 and 58, respectively. It has been suggested that the E. glaucinus karyotype has evolved from the E. perotis karyotype through Robertsonian fusion events. In the present study, the telomeric sequences were detected at the termini of chromosomes in both species. In addition, E. glaucinus also displayed telomeric repeats in centromeric and pericentromeric regions in almost all biarmed chromosomes. Conversely, in E. perotis pericentromeric signals were only observed in two biarmed chromosomes. In both E. glaucinus and E. perotis, such telomeric sequences were observed as part of the heterochromatin. The interstitial sites of telomeric sequences suggest that they are remnants of telomeres of ancestral chromosomes that participated in the fusion event.     

Ambiguities in sound-duration selectivity by neurons in the inferior colliculus of the bat Molossus molossus from Cuba

This study examines duration selectivity in auditory neurons of the inferior colliculus of the bat Molossus molossus (Molossidae, Chiroptera) from Cuba. Three main types of duration selectivity, short-, band-, and long-pass, as previously described in other species, are present in M. molossus. The range of best durations in the inferior colliculus of this species approximates the durations of their echolocation calls, suggesting that, as has been shown in other species of bats and frogs, the filter mechanism that produces duration tuning is selective for species-specific sounds relevant to behavior. Duration coding in M. molossus is not unambiguous because approximately 30% of the short- and band-pass neurons respond best to two different stimulus durations. This bimodal duration selectivity could be explained by time delayed excitatory inputs that coincide with an inhibitory rebound. In addition, the effect of stimulus intensity on duration selectivity was tested. For most of the neurons (78%), duration selectivity was affected by absolute sound pressure level and/or small changes of sound pressure. In this respect, the processing of stimulus duration by collicular neurons seems to be more complex in M. molossus than in other species studied so far.     

The ultrastructure of the atrioventricular junctional tissues in the newborn ferret heart

In this study the structure of the atrioventricular (AV) node and bundle in the newborn ferret heart was examined by light and electron microscopy. At the light microscopic level the AV node could be subdivided into deep and superficial portions. Electron microscopy revealed that both superficial and deep AV nodal cells were characterized by a paucity of myofibrils, desmosomes, fasciae adherentes and gap junctions. Deep AV nodal cells, however, had more surface specializations than did superficial AV nodal cells. In both subdivisions the constituent cells were ellipsoid with tapering end-processes. In contrast to the nodal cells, the newborn AV bundle cells were round to ovoid. The AV bundle cells were organized into large fascicles, and there was a high frequency of anastomosing intercommunication between fascicles. These bundle cells had few myofibrils and a high incidence of apposed plasma membrane. The present morphological findings support the concept that there are significant postnatal morphological changes that occur in the region of the AV junction. These results are also consistent with findings in other species that AV nodal conduction time is similar in newborns and adults, while conduction through the AV bundle increases with age.     

Acarine infracommunities associated with the Mexican free-tailed bat, Tadarida brasiliensis mexicana (Chiroptera: Molossidae) in arid regions of Mexico

The Mexican free-tailed bat, Tadarida brasiliensis mexicana, is one of the most widely distributed bats, and its range includes the whole Mexican territory. Ectoparasites of this bat have been the subject of isolated reports, but no studies of its community ecology have been conducted. The acarine infracommunities associated with this bat were analyzed, comparing bat populations from three arid regions of Mexico: an abandoned factory in Nombre de Dios, Durango; a cave in Santiago, Nuevo León; and a church in Concepción del Oro, Zacatecas. The acarine infracommunity in Nuevo Le6n's bats exhibited the highest levels of diversity as reflected by a higher richness, a lower dominance, and a moderate and relatively homogeneous abundance in this locality in relation to the other two. This pattern is influenced by stable cave conditions relative to artificial habitats. Notwithstanding, further studies are required to determine whether or not different habitat conditions are a primary factor in the process of structuring the acari infracommunities.     

Reproductive biology of the male little mastiff bat,Mormopterus planiceps (Chiroptera: Molossidae), in Southeast Australia

The anatomy, biology, and chronology of reproduction in the male of the long penile form of Mormopterus planiceps was studied in southeast South Australia and Victoria. In the morphology of its primary and accessory reproductive organs, M. planiceps was generally reminiscent of other Molossidae; however, in the specialized (sebaceous) nature of the Cowper's gland ducts, in the presence of para-anal glands, and in the unusual, horizontally bifid glans penis and the greatly elongated os penis, it was distinct from other Molossidae studied to date. Young of the year were not reproductively active. Adults displayed a single annual spermatogenic cycle that commenced in spring (September/October) and culminated in spermiogenesis in autumn (February-May), during which period plasma levels of testosterone overtook androstenedione. Thereafter, spermatogenesis appeared to cease (though scattered sperm were seen in the seminiferous tubules until August), but abundant epididymal sperm reserves persisted until September/(October). The accessory glands were hypertrophied during this period, becoming involuted by October. Although the numbers of animals available for study were small, these observations, together with the appearance of spermatozoa in the ductus deferens in August/September suggested that mating could occur during the interval from autumn to spring. Late winter/spring insemination is normal for molossids from temperate environments. However, protracted spermatogenesis commencing in spring that is not accompanied by the availability of spermatozoa until autumn, and a subsequent apparent extension of fertility (epididymal sperm storage, accessory gland hypertrophy) beyond the testicular gametogenic phase, are aspects of the male reproductive cycle in M. planiceps that have not heretofore been described in another molossid bat.     

The descriptive and functional myology of the fore-limb of the Aardvark (Orycteropus afer, Pallas 1766)

The myology of the fore-limb of the Aardvark, Orycteropus afer (Pallas 1766) (Tubulidentata, Mammalia) is redescribed on the basis of the dissection of two specimens. The results were complemented with data derived from X-ray pictures and a motion picture. Some remarks are made on the digging techniques in the Aardvark and other fossorial mammals. In Orycteropus, the power stroke comprises synchronous bending of shoulder-, elbow and metacarpophalangeal joints. The most important muscles involved are the Mm. cutaneus trunci, latissimus dorsi, pectoralis profundus, triceps brachii, flexor digitorum superficialis and -profundus.     

Fine structural alteration in the atrioventricular junctional conduction tissues of the dog heart during severe ischaemia

To define the fine structural changes produced in the atrioventricular junctional conduction tissues by severe ischaemia, 3 sets of specimens from 37 dogs were examined by light and electron microscopy using a large specimen resin-embedding method. Surgical control material was taken from 18 open-chest animals maintained under anaesthesia for up to 6 h, autolysis control material from 10 excised normal hearts maintained at 37 degrees C in vitro for up to 4 h, and ischaemic material from 8 animals in which the septal and distal left circumflex coronary arteries were occluded for 15 min to 3 h. Surgical control material was found to be within normal limits, whereas both autolysed and ischaemic showed initially mild fine structural alteration, which increased progressively in severity with time and was comparable in both sets. All cell types showed loss of glycogen granules, mitochondrial swelling, dilatation of sarcoplasmic reticulum vesicles, clumping of nuclear chromatin and ultimately varying degrees of generalised cell swelling. Intramitochondrial dense inclusions also were prominent in autolysis but not ischaemia. These changes progressed faster in nodal cells than in His bundle/bundle branch cells, which retained considerable quantities of glycogen for at least 60 min. The slower development of irreversible alteration in His-Purkinje cells suggests that they may be relatively more resistant to ischaemia, whilst the low incidence of intramitochondrial dense inclusions in vivo suggests a beneficial effect of collateral blood flow.     

Embryonic Staging System for the Black Mastiff Bat,Molossus rufus (Molossidae), Correlated With Structure‐Function Relationships in the Adult

An embryonic staging system for Molossus rufus (also widely known as Molossus ater) was devised using 17 reference specimens obtained during the postimplantation period of pregnancy from wild‐caught, captive‐bred females. This was done in part by comparing the embryos to a developmental staging system that had been created for another, relatively unrelated bat, Carollia perspicillata (family Phyllostomidae). Particular attention was paid to the development of species‐specific features, such as wing and ear morphology, and these are discussed in light of the adaptive significance of these structures in the adult. M. rufus can be maintained and bred in captivity and is relatively abundant in the wild. This embryonic staging system will facilitate further developmental studies of M. rufus, a model species for one of the largest and most successful chiropteran families, the Molossidae. Anat Rec, 2009. © 2008 Wiley‐Liss, Inc.     

Topographical and morphometrical study of the atrioventricular junctional area of the cardiac conduction system in the Macaca fascicularis Raffles, 1821

The morphology of the atrioventricular (AV) junctional area is a subject for great controversies. The present work studies this region in 2 hearts of M. fascicularis adult female perfused with Bouin fluid, serial sectioned in frontal plane and stained by van Gieson trichromic method. A three-dimensional wax reconstruction of the AV specialized tissue was performed. The areas of the AV bundle and left bundle branch (LBB) cross-section were calculated by point-counting. The results showed that the junctional AV region in M. fascicularis is approximately similr to the same region in the human heart. The AV node presents compact and transitional portions. The cardiac central fibrous body is well developed and gives off an incomplete septum of connective tissue interposed between the terminal portion of the AV node and the beginning of the AV bundle. The reconstruction showed that the right bundle branch (RBB) is the direct continuation of the AV bundle while the LBB is a broad left side detachment. The average diameters of the AV bundle, LBB and RBB proved to be respectively 867.08 micron and 126.65 micron. The length and the volume of the AV bundle were respectively 406.86 micron and 0.223 mm3.     

Ultrastructure of the sinoatrial area of the heart during the long Q-T syndrome

The conducting myocardia of the sinus node and prenodal working ones of the right atrium, which had been dissected from 6 patients aged 10-40 years with the prolonged Q-T interval syndrome during an operation on implantation of an artificial pacemaker were examined. Acute and chronic destructive changes were found in the conducting and working myocytes of the sinoauricular region in the heart. Some cases displayed abnormal contact interrelationships of myocytes. Destructive changes were observed in non-myelinated and myelinated nerve fibers, microcirculatory bed, and the connective tissue component of the conducting and working myocardium. The abnormalities found in the cardiac sinoauricular region are discussed to be a possible substrate for the development of life-threatening arrhythmias in patients with the prolonged Q-T interval syndrome.     

Coagulation parameters of captive mountain gazelle (Gazella gazella Pallas, 1766; Bovidae: Antilopinae) and Nubian ibex (Capra ibex nubiana Cuvier, 1825; Bovidae: Caprinae)

The coagulation profiles of 36 mountain gazelles (Gazella gazella) aged 2–6?years, and 17 Nubian ibexes (Capra ibex nubiana), aged 1–4?years, were evaluated and compared. The following parameters were determined in both species: prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen concentration (FIB), and clotting factors VII, VIII:C, IX, X, and XI. Thrombin clotting time (TCT) was also determined in mountain gazelles. The results indicated significant interspecies differences in most parameters, with lower PT, aPTT, and factors VII, IX, and XI and higher factor XIII:C activities in the Nubian ibex than the mountain gazelle. Gender seemed to have a limited influence on these parameters within each species. Both species had higher plasma FIB and factor VIII:C activity relative to humans. This study is the first record of coagulation variables in these two species of wild Arabian desert ruminants.     

Unique Turbinal Morphology in Horseshoe Bats (Chiroptera: Rhinolophidae)

The mammalian nasal fossa contains a set of delicate and often structurally complex bones called turbinals. Turbinals and associated mucosae function in regulating respiratory heat and water loss, increasing surface area for olfactory tissue, and directing airflow within the nasal fossa. We used high‐resolution micro‐CT scanning to investigate a unique maxilloturbinal morphology in 37 species from the bat family Rhinolophidae, which we compared with those of families Hipposideridae, Megadermatidae, and Pteropodidae. Rhinolophids exhibit numerous structural modifications along the nasopharyngeal tract associated with emission of high duty cycle echolocation calls via the nostrils. In rhinolophids, we found that the maxilloturbinals and a portion of ethmoturbinal I form a pair of strand‐like bony structures on each side of the nasal chamber. These structures project anteriorly from the transverse lamina and complete a hairpin turn to project posteriorly down the nasopharyngeal duct, and vary in length among species. The strand‐like maxilloturbinals in Rhinolophidae were not observed in our outgroups and represent a synapomorphy for this family, and are unique in form among mammals. Within Rhinolophidae, maxilloturbinal size and cross‐sectional shape were correlated with phylogeny. We hypothesize that strand‐shaped maxilloturbinals may function to reduce respiratory heat and water loss without greatly impacting echolocation call transmission since they provide increased mucosal surface area for heat and moisture exchange but occupy minimal space. Alternatively, they may play a role in transmission of echolocation calls since they are located directly along the path sound travels between the larynx and nostrils during call emission. Anat Rec, 300:309–325, 2017. © 2016 Wiley Periodicals, Inc.     

Maxilloturbinal Aids in Nasophonation in Horseshoe Bats (Chiroptera: Rhinolophidae)

Horseshoe bats (Family Rhinolophidae) show an impressive array of morphological traits associated with use of high duty cycle echolocation calls that they emit via their nostrils (nasophonation). Delicate maxilloturbinal bones inside the nasal fossa of horseshoe bats have a unique elongated strand-like shape unknown in other mammals. Maxilloturbinal strands also vary considerably in length and cross-sectional shape. In other mammals, maxilloturbinals help direct respired air and prevent respiratory heat and water loss. We investigated whether strand-shaped maxilloturbinals in horseshoe bats perform a similar function to those of other mammals, or whether they were shaped for a role in nasophonation. Using histology, we studied the mucosa of the nasal fossa in Rhinolophus lepidus, which we compared with Hipposideros lankadiva (Hipposideridae) and Megaderma lyra (Megadermatidae). Using micro-CT scans of 30 horseshoe bat species, we quantified maxilloturbinal surface area and skull shape within a phylogenetic context. Histological results showed horseshoe bat maxilloturbinals are covered in a thin, poorly vascularized, sparsely ciliated mucosa poorly suited for preventing respiratory heat and water loss. Maxilloturbinal surface area was correlated with basicranial width, but exceptionally long and dorsoventrally flat maxilloturbinals did not show enhanced surface area for heat and moisture exchange. Skull shape variation appears to be driven by structures linked to nasophonation, including maxilloturbinals. Resting echolocation call frequency better predicted skull shape than did skull size, and was specifically correlated with dimensions of the rostral inflations, palate, and maxilloturbinals. These traits appear to form a morphological complex, indicating a nasophonatory role for the strand-shaped rhinolophid maxilloturbinals. Anat Rec, 2018. © 2018 American Association for Anatomy.     

ZOO-FISH Analysis in a Species of the Order Chiroptera: Glossophaga soricina (Phyllostomidae)

Glossophaga soricina is a flower-visiting bat which lives in the neotropics. The diploid chromosome number is 2n = 32 with a fundamental number of autosomal arms, FN, of 60. G. soricina belongs to the Microchiroptera which have a lower diploid DNA content and a higher AT composition in their DNA compared with other mammals. By ZOO-FISH analysis with human chromosome-specific DNA probes, the human autosomes were found conserved in 41 segments. This is an arrangement similar to other mammals which have been analyzed. Several chromosomal associations already known from ZOO-FISH studies in other species were also present in G. soricina. This revised version was published online in August 2006 with corrections to the Cover Date.     

Detection of Acari in Chiroptera in the Neubrandenburg District (East Germany)

The following 10 species of bat ticks and mites have been determined in the material collected in the territory of the district: Ixodes (E.) vespertilionis, Argas (C.) vespertilionis, Spinturnix myoti, S. mystacinus, S. acuminatus, S. plecotinus, Macronyssus flavus, Steatonyssus (S.) periblepharus, S. (S.) spinosus and Notoedres chiropteralis. Some data concerning the frequency of the occurrence of mites from the family Spinturnicidae are given.     

人体心脏房室结、房室环及主动脉后结的巨微解剖

目的解剖分离人体心脏房室结和房室环的结构,阐述它们的形态特征及相互关系。方法通过体视显微镜解剖12例人体心脏的房室结、主动脉后结及房室环,再进行组织学观察,并绘图演示它们的结构关系。结果在二尖瓣环和三尖瓣环靠近冠状窦前缘处分别暴露了左、右房室环(12/12),直径分别为(0.69±0.12)mm、(0.78±0.13)mm。此处的左、右房室环穿行在房室隔内的心房肌与心室肌之间的间隙中,向房室结方向延伸。主动脉后结在主动脉根后方的房间隔中被探查到(7/9),它的后上方的房间隔间隙中有肌纤维与其相连,它的前下方分出左、右房室环,并且此处的左环比右环粗。在中心纤维体后方的心内膜下的深部,主动脉后结与房室结之间有直接的心肌组织连接通路,这条通路有别于另两条通路(左、右房室环)。结论主动脉后结和房室环可通过体视显微镜解剖暴露,主动脉后结与房室结之间有3条通路。